The invention relates to a power semiconductor module and concerns, in particular, a power semiconductor module having a carrier plate, on which at least four substrates are arranged, and having a first and a second busbar having two conductive plates, which are arranged such that they are at a distance from one another and are insulated from one another, for respectively carrying a lower and an upper electrical potential, said busbars each being fitted with outer connecting lugs which face away from the substrates and inner connecting lugs on the substrate side. Such a power semiconductor module is disclosed in EP 0 427 143 B1.
Power semiconductor modules having half-bridges are used, for example, to construct three-phase converters for electrical drives. Such converters contain a rectifier section, a DC intermediate circuit having a capacitor, and an inverter section. The power section of the inverter can be constructed from half-bridge circuits. Half-bridge circuits which contain, for example, fast-switching IGBT transistors as semiconductor switches and very fast freewheeling diodes are suitable for this purpose.
In the respective half-bridge circuits, it is particularly important to symmetrize the commutation operations:                the IGBT transistor switches off and the current commutates into the diode, and        the IGBT transistor switches on and the current commutates into the IGBT transistor.        
For these and other reasons, there is a need for the present invention.